An example of such a kind of conventional ion implantation apparatus is shown in FIG. 10. An ion implantation apparatus equivalent thereto is described, for example, in Patent Document 1. In the present specification and drawings, a traveling direction of an ion beam 4 in design is a Z direction, and two directions substantially orthogonal to each other in a plane substantially orthogonal to the Z direction are an X direction and a Y direction. For example, the X direction and the Z direction are horizontal directions, and the Y direction is a vertical direction. In the other words, such a “traveling direction in design” is a predetermined traveling direction, that is, a traveling direction for original travel.
This ion implantation apparatus mass-separates an ion beam 4 generated from an ion source 2 and having a small sectional shape as foundation of a ribbon-shaped ion beam through a mass separator 6, accelerates or decelerates it through an accelerator/decelerator 8, energy-separates it through an energy-separator 10, scans it in the x direction through a scanner 12, forms it into a parallel beam through a beam paralleling device 14, irradiates a target (e.g., semiconductor substrate) 24 supported to a holder 26, and implants ions into the target 24. The target 24 is mechanically reciprocating scanned (reciprocating driven) together with the holder 26 in a direction along the Y direction by a target driving device 28 within an emission area irradiated with the ion beam 4 from the beam paralleling device 14.
The beam paralleling device 14 cooperates with the scanner 12 that scans the ion beam 4 by magnetic field or electric field (in this example, magnetic field), bends it to be substantially parallel to a reference axis 16 by magnetic field or electric field (in this example, magnetic field) to form it into a parallel beam, and makes the ribbon-shaped ion beam 4 (see FIG. 11) in which a size in the X direction is larger than a size in the Y direction orthogonal to the X direction. Although the ion beam 4 has the ribbon shape, it does not means the size in the Y direction is as thin as paper. For example, the size in the X direction of the ion beam 4 is about 35 cm to 50 cm, and the size in the Y direction is about 5 cm to 10 cm. The beam paralleling device 14 is called as a beam paralleling magnet in case of using magnetic field described in the present example.
In the example of the ion implantation apparatus, the target 24 is irradiated with the ribbon-shaped ion beam 4 through the scanning in the X direction. However, the ribbon-shaped ion beam 4 may be generated from the ion source 2, and then the target 24 may be irradiated with the ribbon-shaped ion beam 4 without the scanning in the X direction.
Patent Document 1: Japanese Patent Laid-Open Publication No. 8-115701 (paragraph 0003, FIG. 1)